Yes, gambling sites provide us with server seeds that can be verified.
But how do we really know that these seeds are used in actual gambling process?
Isnt it possible they are just displaying server seeds and hashes that we can verify but in reality the server seeds they are using in the back-end functions of the game are actually different/rigged?
Yes I agree with you no one knows for sure about it because only a few people understand about server seeds and hash. Although some of them say that probably fair gambling sites is provable but im not believe 100%.